# CARD_ReadFlashAsync

## C Specification

      #include <nitro/card.h>

      static inline void	CARD_ReadFlashAsync(u32 src, void *dst, u32 len, MIDmaCallback callback, void *arg);

## Description

This function asynchronously loads data from the FLASH device. This function immediately returns the control.

When using this function, the access bus must be locked in advance using the `CARD_LockBackup` function.

The `CARD_WaitBackupAsync` function is used when waiting for the processing to complete. Call the `CARD_GetResultCode` function after completion in order to determine the results of the processing.

This function performs communications internally with the I/O processor through PXI. Be aware that the process will not complete unless the PXI interrupt is enabled.

## Arguments

`src` | The FLASH address of the transmission source
`dst` | The memory address of the transmission destination
`len` | The byte length of the data to be read out
`callback` | The callback function at the time of completion. Designate a NULL when this is not needed.
`arg` | The arguments passed to the callback function at the time of completion. This is simply ignored if a NULL was designated in the callback.

## Return Values

None.

## Internal Operations

This function executes asynchronous processes by use of the internal thread. For further details about this thread, please refer to the description of the `CARD_GetThreadPriority` function.

## See Also

`CARD_IsBackupFlash CARD_WaitBackupAsync, CARD_GetResultCode, CARD_ReadFlash, CARD_WriteFlash, CARD_VerifyFlash, CARD_WriteAndVerifyFlash, CARD_GetThreadPriority`

## Revision History

11/02/2004 Corrected a link.
08/23/2004 Revised the links due to changes to the function.
08/18/2004 Initial version.